Engines include a number of rotational components such as crankshafts. The rotary oscillations of the crankshaft lead to rotational speed oscillations of the internal combustion engine, and are also transmitted via the timing drive or camshaft drive to the camshaft, the camshaft itself also being an oscillatory system which can excite vibration in further systems, such as valve mechanisms. The transmission of vibration to other ancillary units via components driven by the crankshaft is also possible. In addition, the oscillations of the crankshaft are transmitted to the drive train, via which they may be transmitted onwards to the transmission and the drive shafts and as far as the tires of a vehicle. Centrifugal pendulum devices may be used in engines to attenuate vibrations in the crankshaft and drive train.
The German published patent application DE 10 2006 028 556 A1 describes such a centrifugal pendulum device. The device is positioned in a drive train of a motor vehicle and used to absorb and/or damp rotary oscillations in the drive train. The centrifugal pendulum device of DE 10 2006 028 556 A1 has a pendulum mass carrier rotatable about an axis of rotation and at least one pendulum mass pair comprising two pendulum masses arranged movably on the pendulum mass carrier opposite one another and at a distance from the axis of rotation. The pendulum masses are connected to the pendulum mass carrier, the pendulum masses having arcuate openings in which rollers provided on the pendulum mass carrier are supported and guided. The arcuate openings form the tracks for the rollers and guide the movement of the pendulum masses. Prior art FIGS. 1a, 1b and 1c show in a simplified schematic representation a prior art centrifugal pendulum device as disclosed in DE 10 2006 028 556 A1, FIG. 1a showing the prior art centrifugal pendulum device in the so-called zero state, FIG. 1b shows the prior art device in a working position, and FIG. 1c shows the prior art device in a position when the vehicle stationary, that is, when the internal combustion engine inoperative and not producing output power. Another centrifugal pendulum device is described in the German published patent application DE 10 2011 105 029 A1.
The centrifugal pendulum device 21 represented in the prior art figures has a pendulum mass carrier 23 rotating about an axis of rotation 22 and two pendulum masses 24a, 24b arranged movably on the pendulum mass carrier 23 and forming a pendulum mass pair 24. The pendulum masses 24a, 24b have arcuate openings 26a, 26b, are located opposite one another, are spaced from the axis of rotation 22, and are mounted and positively guided kinematically by means of roller pins 25a, 25b of the pendulum mass carrier 23 engaging in the openings 26a, 26b. The pendulum masses 24a, 24b of FIG. 1b are located opposite one another and the pendulum masses 24a, 24b are spaced away from the axis of rotation 22 as soon as their centers of gravity are at a distance from the axis of rotation 22. The arcuate openings 26a, 26b represent the tracks 26a, 26b for the roller pins 25a, 25b and therefore guide movement of the pendulum masses 24a, 24b. 
When the internal combustion engine is inoperative and the vehicle at a standstill, and when the pendulum mass carrier is stationary, the pendulum masses 24a, 24b can adopt the position represented in FIG. 1 c and thus form an unbalanced mass. This gives rise to problems, especially when the pendulum mass carrier 23 is set in rotation again. For example, when the internal combustion engine is started and the pendulum masses 24a, 24b must first settle into a working position as represented in prior art FIG. 1b during this start-up process, that is, as the rotary motion begins. Increased noises, combined with high stress on the pendulum mass bearings, in particular the roller pins, may result from the prior art centrifugal pendulum device illustrated in FIGS. 1a, 1b, and 1c. 
As such in one approach, a centrifugal pendulum device in an engine is provided. The centrifugal pendulum device includes a pendulum mass carrier, a moveable coupling element rotatably coupled to the pendulum mass carrier via a first bearing element, the coupling element forming a continuous piece of material, and two pendulum masses spaced away from one another and rotatably coupled to the coupling element via a second bearing element and a third bearing element.
Jointly rotationally coupling the pendulum masses via common coupling elements enables one of the masses to compensate for the other when the first mass is urged into an offset position, such as when the engine is inoperative and not producing a rotational output. In this way, the pendulum masses may be cooperatively moved to provide mass balance in the centrifugal pendulum device. As a result, vibration cause by unbalance masses during engine restart is reduced (e.g., substantially eliminated), thereby reducing noise, vibration, and harshness (NVH) in the engine. Moreover, rotationally coupling the mass carrier, pendulum masses, and coupling element reduces the wear in the coupling mechanism when compared to prior centrifugal pendulum devices. As a result, the longevity of the centrifugal pendulum devices is increased.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. Additionally, the above issues have been recognized by the inventor herein, and are not admitted to be known.